Extension of recombinant human RANTES by a single residue at the amino terminus is
sufficient to produce a potent and selective antagonist. RANTES is a proinflammatory
cytokine that promotes cell accumulation and activation in chronic inflammatory diseases.
When mature RANTES was expressed heterologously in Escherichia coli, the amino-
terminal initiating methionine was not removed by the endogenous amino peptidases. This
methionylated protein was fully folded but completely inactive in RANTES bioassays of …